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Overview

Description

Wide Open Track Attack: With the agility of a 125 and a healthy dose of extra power, the KTM 150 SX is a lively package ready to take on the 250 cc 4-strokes. From within its completely reworked new chassis, the compact, lightweight engine produces class-leading torque and power. Everything about this motorcycle screams high-performance fun and it goes into battle as the ultimate on-track competitor.

Engine & Exhaust

The pure exhilaration that this bike's engine delivers warranted further development and continued production. As it shares many of its key components with the class-leading 125, the cylinder, cylinder head and piston unit can now also be fitted on a 125cc engine base, converting it to a 150 SX without having to replace the crankshaft. Compact and powerful, this innovative 2-stroke engine is a lightweight powerhouse that makes perfect sense.

Cylinder: This compact cylinder with a 58mm bore features a cutting-edge power valve unit with a sophisticated mechanism for the lateral support exhaust ports. Matched to a twin-component cylinder head, it is KTM's secret to all-round grunt. The layout of the water jackets in the cylinder and head guarantees efficient heat dissipation when the going gets tough.

Crankcases and engine covers: For the latest engine generation the KTM engineers designed lightweight die-cast engine cases featuring a high crankshaft position located close to the center of gravity, which results in optimal mass centralization and outstanding rideability.

Transmission: A robust 6-speed transmission was designed specifically for the small 2-stroke engine, its gear ratios are perfectly in sync with the 150's power band. The latest production technologies allow for compact dimensions and minimal weight. An advanced ´No Dirt´gear lever design prevents mud from clogging the folding tip for reliable shifts even in the worst conditions.

Carburetor: The KTM 150 SX is fitted with a MIKUNI TMX carburetor. This 38mm flat slide carb lives to provide smooth and controllable power all the way up to the rev limitation. With a new intake manifold the carburetor is turned 7° in order to reduce the overflow of fuel. And it's less sensitive to different altitudes and temperatures, so you can pin it wherever, whenever.

Ignition: All 2-stroke models feature a new CDI control unit with an advanced hardware which improves the starting behavior of the engine. The ignition curves remain unchanged.

Crankshaft: This reliable piece of engineering has been skillfully balanced to guarantee minimal vibrations. In its latest form, it allows a decrease of the displacement to 125cm 3 just by replacing cylinder, piston and head. There's no longer the need to change the crankshaft if you want to change displacement. Two-in-one in no time.

Cooling: KTM's proven cooling system routes the coolant from the cylinder head through the frame triangle, directly to aluminum radiators made by WP. A new filler cap system and are stiffer alloy construction increase the durability and reliability of the cooling system. Due to flow optimized internal circulation and CFD-calculated air ventilation, the system is superbly efficient. In addition, well thought-out radiator guards integrated in the front part of the shrouds provide protection in a crash.

Exhaust: The engineers meticulously tuned the resonator chamber for maximum torque and power, so this screamer is as tough as it is strong.

Chassis Features

The KTM 150 SX is just made to be ridden aggressively, resulting in the development of a new chassis that is light and responsive enough to further enhance its dynamic reputation. For 2019, the KTM 150 SX features a new lightweight, high-tech steel frame that not only responds well to aggressive inputs, but has also been optimized to provide exceptional feedback to the rider. The new flex characteristics soak up those unwanted hits while also delivering excellent agility and high-speed stability. As a whole, this new chassis gives the rider the confidence to be 100% in charge of the ride.

Frame: The high-tech, lightweight chrome-moly steel frame has a knack for easy handling, outlandish rideability, precise cornering and excellent stability. You can also count on high torsional rigidity and low longitudinal stiffness. This results in better absorption of the energy created from the front and rear suspension, sucking up jumps and bumps. In short: more comfort and less rider fatigue. Laterally attached, engine head stays (the connection between cylinder head and frame) are now made of lightweight aluminum. They contribute to more precise cornering and a reduced vibration level. The engineers were able to pull off all that, while making their frame 2.2 pounds lighter than that of the lightest competitor on the market. In addition, it is easier to maintain, easier to work on and supplies more space for the tank and other components. The bike also features an extra-light subframe made of aluminum, which tiptoes the scales at less than 2 pounds.

Front suspension: All full-size SX models are fitted with the super-lightweight WP AER 48 front fork. It is a 48 mm USD air-sprung fork with separate functions for each fork leg, meaning damping functions are on the right side and the air spring is on the left. The left leg features a two-chamber system with a capsuled air cartridge, helping prevent loss of air pressure. Essentially, this means that in the rare case of a leaking outer seal, the internal cartridge pressure keeps the bike in a normal position. The air spring is exceptionally easy to use and can be adjusted to any rider weight via a single air valve and the air pump that is supplied with the bike. The right fork leg integrates a damping cartridge to fit single damping leg requirements and can be adjusted to the track conditions and the rider's preferences. (compression from top, rebound from bottom, 30 clicks each). For 2019, new settings on the damping side have improved the damping characteristics, providing great front end feel and control.

Triple clamp: All SX models feature top quality, CNC-machined triple clamps and have become somewhat of a KTM trademark. For 2019, the triple clamp has been reworked with stiffer upper clamps (22 mm offset for all models) to suit the reworked frame stiffness and flex characteristics of the latest WP AER forks. The result is a front end that works in perfect harmony with the frame, improving overall handling and stability. The rubber damped handlebar fixation reduces vibration and also allows for some adjustment with 2 different mounting positions. An hour meter is fitted as standard on the upper triple clamp on all SX models, keeping the rider informed of the number of hours spent tearing up the track and when the next service is due.

Rear suspension: The WP shock absorber has been developed with the entire frame and swingarm architecture in mind, including the linkage and the WP AER 48 front fork. It features machined and black anodized components and is a valuable, high-end product compared to roughcast reservoirs. A new, confidence inspiring setting with improved damping characteristics perfectly matches the front-end setup and its striking WP color scheme lets everyone know you have excellent taste in suspension.

Brakes: You can't brake any harder, better, faster or stronger. These high-tech Brembo babies are combined with lightweight wave discs made by Galfer. For 2017, the rear brake features a 10mm longer brake pedal and you get new, less aggressive brake pads all round.

Fuel tank: A lightweight polyethylene tank with a capacity of 1.85 gallons. The fuel tank cap has an inside thread, which makes for easy and reliable closure.

Airbox: The airbox design offers maximum protection of the air filter while ensuring maximum airflow. The large twin-air filter is mounted in a stiff cage, which at the same time holds the system in place. This design is so simple you could still pop a fresh one in with a face full of mud. Without tools. In seconds.

Ergonomics & Comfort

When it comes to attacking the track, chasing faster times with every lap,there is no better weapon than the KTM 150 SX. Its performance-inspired design allows the rider to shift his weight quickly and easily, working in perfect harmony with the motorcycle. KTM has focused extensively on creating bodywork and ergonomics that are shaped for high-level performance, ensuring a riding position that offers the best riding position for control. A rider's main interaction with the bike isthrough the bodywork, footpegs, handlebars. No compromises were made in these important areas and only the best quality products and designs can be seen on all SX models. KTM produces dynamically fast motorcycles and every effort goes into making sure the rider has the ability to confidently control it.

Seat: All SX models have a newly shaped seat, designed to match the improved ergonomics. The seat cover features newly developed silicone strips that provide better feel and grip for the rider. The seat is conveniently fixed to the bike using one long, lateral screw, making it safe and easy to handle.

Handlebar: KTM engineers sure know how to handle handlebars. This tapered one, made of high-strength aluminum by NEKEN, is fixed in damped rubber mounts and has two different positions. From 2017 onwards, the lower handlebar clamps are separated, while on the upper side a new bridge-type clamp guarantees more torsional stiffness. It's also easier to replace the bar in case it gets twisted in a nasty crash. ODI lock-on grips make grip changes easy which does not require any wire or glue to be secured.

Footpegs: Sophisticated ´No Dirt´ footpegs prevent smudging up the pegs, even when digging in deep ruts. Looking for a higher riding position? Then just mount the footpegs of the 2018 EXC models, which are 6mm higher than the SX versions.

Bodywork & Graphics

Those who ride a KTM 150 SX thrive on the extra power it delivers, while still having the dynamic agility and feel that a 125 cc offers. These riders are always pushing themselves and their machines to the limit and need the freedom of movement to position the bike where they want it on the track. With input from KTM factory riders, KTM R&D as well as Kiska Design, the bodywork on the entire SX range achieves perfect harmony between rider and bike, providing the manoeuvrability the rider expects and the control he needs. The bodywork also contains intelligent design elements, like the I-beam structure on the front and rear fenders, which guarantee maximum stability without adding any extra weight. The new graphics suit the aggressive nature of the bike and further enhance the high performance style of the bodywork.

Decals: New graphics convey the READY TO RACE character of the 2017 SX model line.

Software & Electronics

Absolute performance purity is the name of the game when it comes to electronics and the new KTM 150 SX. Undiluted 2-stroke simplicity, with an hour meter to keep a check on how long you've been shredding and an optional rev counter to assist with perfect setup.

Engine

Design: 1-cylinder, 2-stroke engine

Displacement: 143.9 cm³

Bore: 58 mm

Stroke: 54.5 mm

Starter: Kickstarter

Transmission: 6-speed

Clutch: Wet multi-disc clutch, hydraulically actuated

EMS: Kokusan

Chassis

Frame design: 25CrMo4 steel central-tube frame

Front suspension: WP-USD, AER 48, Ø 48 mm

Rear suspension: WP shock absorber with linkage

Front brake: Disc brake

Rear brake: Disc brake

Front brake disc diameter: 260 mm

Rear brake disc diameter: 220 mm

Chain: 5/8 x 1/4"

Steering head angle: 63.9 °

NOTES:

The illustrated vehicles may vary in selected details from the production models and some illustrations feature optional equipment available at additional cost. All information concerning the scope of supply, appearance, services, dimensions and weights is non-binding and specified with the proviso that mistakes, printing, setting and typing errors may occur; such information is subject to change without notice. No rights may be derived from incorrect statements.